Database Administrators Stack Exchange is a question and answer site for database professionals who wish to improve their database skills and learn from others in the community. It's 100% free, no registration required.

3 Answers
3

It sounds like you've got a huge transaction that has remained open which has done a lot of work. Run DBCC OPENTRAN on the database and see how long the oldest transaction has been open for. You'll probably need to kill that transaction (or have the user commit if it's someone in Management Studio). Then the log will clear automatically.

To start with - check the values of log_reuse_wait and log_reuse_wait_desc columns in the sys.databases catalog view. You can find if anything is preventing log truncation and act based on that. You can find a list of available values and their meaning here: